1. Technical Field
The present disclosure relates to a speaker and an audio-visual system.
2. Description of the Related Art
In recent years, wideband speakers (hereinafter referred to as magnetic fluid speakers) that use divided suspensions and magnetic fluid and that are capable of reproducing low-pitched sound though being small-sized have been developed.
FIG. 10A is a diagram illustrating a cross-section of a speaker 400 that is a conventional speaker disclosed in International Publication No. 2009/066415 and that makes use of magnetic fluid and divided suspensions. FIG. 10B is a cross sectional view, taken along line XB-XB, of the speaker of FIG. 10A. The speaker illustrated in FIGS. 10A and 10B includes a yoke 20, a magnet 21, a plate 22, a diaphragm 30, suspensions 24a and 24b, a voice coil 26, a sound conduit tube H2, ribs L1, and magnetic fluid 27.
In the above configuration, the suspensions 24a and 24b that support the diaphragm 30 in a vibratable manner are provided at different positions on the periphery of the diaphragm 30. In the case where the speaker is reduced in size, accordingly, stiffness can be reduced and thus a minimum resonant frequency of the speaker can be lowered by adjusting widths and/or thicknesses of the suspensions 24a and 24b. With the sealed-in magnetic fluid 27, additionally, interference between sound waves and rolling that occur on surfaces of the diaphragm 30 can be reduced. By use of the speaker that makes use of the magnetic fluid 27 and the divided suspensions 24a and 24b, as described above, the wideband speaker though being small-sized that is capable of reproducing low-pitched sound can be provided.
Japanese Unexamined Patent Application Publication No. 2008-160644 describes an example of a hearing aid in which a damper is provided in a sound conduit tube.